When did Paul say a believer should refuse to eat meat that might be polluted by idols?
Paul taught that a believer should refuse to eat meat potentially polluted by idols when the believer had any idea that the animal sacrifice offered to a pagan god had somehow tainted the meat. If no such concern existed, Paul himself was not bothered, recognizing those pagan gods had no power to affect it.
Les explains that when the Jerusalem leaders agreed Gentiles could be saved by Paul’s Gospel apart from the Law of Moses, they asked that Gentile believers abstain from pollution of idols (s426–s432). Les notes this means little today because rank idolatry is not around us, but in Paul’s day paganism and animal sacrifices to pagan gods were everywhere (s433–s439). Many sacrificed sheep and goats ended up in the marketplace (s442–s445). Les points out that even today in Middle Eastern marketplaces, carcasses hang and women cut off chunks of meat to cook (s446–s458). Back then, Paul said it did not bother him, because one had to recognize those pagan gods had no power and could not affect the meat. But if a person had any idea that the animal sacrifice to a pagan god had somehow been tainted, then they should not eat it (s459–s466).